High precision or high velocity break snap acting switches using modular basic switch components



1966 c. o. FINNEGAN ETAL 3,29 ,464

HIGH PRECISION OR HIGH VELOCITY BREAK SNAP ACTING SWITCHES USING MODULAR BASIC SWITCH COMPONENTS Filed March 2, 1965 5 Sheets-Sheet 1 INVENTORS CYRlL O. FINNEGAN ERICK KOTHE Dec. 1966 c. o. FINNEGAN ETAL 3,290,464

HIGH PRECISION OR HIGH VELOCITY BREAK SNAP ACTING SWITCHES USING MODULAR BASIC SWITCH COMPONENTS INVENTORS CYRlL 0' FINNEGAN ERICK KOTHE FIGB 1966 c. o. FINNEGAN ETAL 3,

HIGH PRECISION OR HIGH VELOCITY BREAK SNAP ACTING I SWITCHES USING MODULAR BASIC SWITCH COMPONENTS Filed March 2, 1965 5 Sheets-Sheet :5

INVENTORS FIGIO United States Patent 3,290,464 HIGH PRECISION 0R HIGH VELOCITY BREAK SNAP ACTING SWITCHES USING MUDULAR BASIC SWITCH COMIPQNENTS Cyril 0. Finnegan, Normal, and Erich Kathe, Schiller Park, IEL, assignors to General Electric Company, a corporation of New York Filed Mar. 2, I365, Ser. No. 436,696 14 Claims. (Cl. 200-67) This invention relates to electrical snap switches and more particularly to improved modular snap actuating switch constructions capable of providing high precision switching action and high velocity contact separation.

Different design criteria affect the selection of switches intended to function in different systems and for controlling different types of electrical loads. In one type of system an overriding consideration may be the distance through which the actuating member must travel in order to actuate the switch unit and the precision of the point at which the switch actuation occurs. In another type of system a dominant factor in the selection of :a switch mechanism may be the speed at which the contacts separate. Where significant arcing may occur between the separating contacts of the switch due to environmental or load factors, it is generally desirable for the contacts to disengage quite rapidly in order to minimize the effects of arcing.

These design criteria are sometimes mutually exclusive. A precision switch mechanism which is operable by a short actuating stroke may be characterized by low contact pressures near the point of contact separation. On the other hand, switches designed to provide a high speed or velocity break between contacts by virtue of a stored actuating force typically require a larger actuation stroke and may be characterized by a less critical point of actuation. Consequently, it has in the past been customary to select different types of switch mechanisms for duty under different conditions of electrical load or of system environment. It has therefore been necessary for those in the snap switch industry to stock different types of switches with equivalent electrical ratings in order to accommodate the need for different types of switching demands as they occur.

This invention contemplates the provision of a modular switch construction operable in either of two different modes. In one mode of operation switches constructed according to this invention exhibit high precision in the actuation of the switch contacts upon a precise displacement of the switch operating member. In another mode of operation switches constructed in accordance with this 3,Z%,4fi4 Patented Dec. 6, I966 their original condition after the release of the switch actuator.

By way of a brief summary of an illustrative embodi ment of the invention, a switch unit is provided which includes an insulating housing formed of two parts enclosing a central chamber. Two electrical terminals having upper and lower spaced sections carrying fixed contacts are supported at opposite sides of one end of an elongated contact-carrying snap spring. The snap spring is supported at its opposite end by a terminal member to which it is rigidly attached. The contact-carrying snap spring includes a pair of relatively flexible outer tension sections and a central substantially rigid compression section interconnected at the contact-carrying end. Between a free end of the compression section and the fixed end of the contact-carrying snap spring a channel-shaped resilient member is placed under compression with pivotal connections at each end. The channel-shaped compression member constitutes :a portion of a resiliently deflectible operator. Another portion of the operator includes a cantilever spring trapped at one end in a portion of the housing and connected to the channel-shaped spring member portion at its other end. The arrangement is such that the movable end of the contact-carrying snap spring normally engages the lower one of the fixed contacts and the cantilever spring portion of the resilient operator is substantially unstressed. A reciprocable pushbutton actuator extends through the housing into engagement with a portion of the resilient operator. Depending upon the portion of the operator engaged by the reciprocable plunger, the switch mechanism operates either as a high precision switch or as :a high velocity switch with high contact pressure up to the instant of contact separation. After actuation of the switch mechanism and release of the actuator the cantilever spring forces the switch contacts to return to their original condition.

Although the invention is not to be limited except by a fair interpretation of the claims appended hereto, further details of the invention as well as additional objects and advantages will be more clearly discernible in connection with the following detailed description of several embodiments of the invention taken together with the accompanying drawings wherein: I

FIGURE 1 is a plan view of one embodiment of the invention with part of the switch housing removed to display the internal construction of the switch mechanism;

FIGURE 2 is a view similar to FIGURE 1 showing the internal condition of the switch mechanism after actuation;

FIGURE 3 is an exploded perspective view of portions of the switch mechanism shown in FIGURES 1 and 2 and invention operate as high velocity break switches with the relatively movable contacts experiencing during contact separation a very rapid transfer of contact force through zero tip pressure regardless of the speed of movement of the switch actuating member.

It is among the objects of this invention to provide im proved snap actuating switches employing modular basic switch components and operable in either of the aforesaid switching modes.

It is a still further object of the invention to provide improved snap acting switch constructions characterized by a simplicity of construction and assembly and marked by a very rapid switching action to reduce the effects of potential arcing at the contacts.

Yet another object of the invention is to provide improved snap switch constructions characterized by high precision actuation points provided by a simplified and highly reliable mechanism.

A still further object of the invention is the provision of highly reliable and simplified snap acting switch constructions providing a positive return of the switch contacts to revealing additional detail;

FIGURE 4 is :a view similar to that of FIGURE 1 showing an alternate form of the invention;

FIGURE 5 is a view of the switch mechanism shown in FIGURE 4 with the switch mechanism in the actuated condition;

FIGURE 6 is an isometric view of two elements of the switch mechanism shown in FIGURES 4 and 5 revealing additional details of their construction;

FIGURE 7 is a view similar to that of FIGURE 5 but showing a substituted switch operating member for actuating the switch mechanism in an alternate mode of operation;

FIGURE 8 is a view similar to FIGURES 1 and 4 showing an alternate formof the invention;

FIGURE 9 is a view of the switch construction shown in FIGURE 8 with the switch shown in the actuated condition;

FIGURE 10 is an exploded perspective view of certain elements of the switch mechanism shown in FIGURES 8 'free end 41 and 9 revealing additional details of their construction;

- URES 1 and 2, there may be seen a switch housing generally designated at 20 with its side cover removed to display the inner construction of the snap switch. The housing 20, which is preferably formed of an insulating composition such as a phenolic resin product, contains a hollow chamber 21 having a number of slots communicating therewith from the outside of the housing. Within slots 22 and 23 are positioned terminal members 24 and 25 having fixed contacts 26 and 27 respectively mounted on their innermost ends within the chamber 21. Terminal members 24 and 25 are preferably formed to have a configuration mating with that of the slots in which they are positioned to prevent unnecessary movements and to define substantially fixed positions for the fixed contacts mounted thereon.

Within a third slot 28 is positioned a common terminal member 29 similarly fixed in position by an interfitting engagement with the contours of slot 28. Terminal members 24, 25 and 29 are preferably provided at their outermost ends with suitable means not illustrated enabling their connection with electrical conductors of a circuit to be controlled. An elongated snap spring 31 is rigidly secured to the innermost end of terminal member 29 as by riveting the projection 32 of terminal member 29 which extends through aperture 33 in the snap spring. At its opposite end, which is movable, the snap spring 31 carries a pair of movable contacts 34 and 35 for cooperative engagement with fixed contacts 26 and 27 respectively.

The configurations of the snap spring 31 and of certain other members cooperating therewith are best seen in the exploded perspective view of FIGURE 3. The snap spring shown in this illustrated embodiment includes a pair of flexible outer tension sections 36 and 37. Within a slot 38 which separates the tension sections 36 and 37, a compression section 39 extends from the contact-carrying end of the snap spring 31 toward the opposite end thereof and terminates in a free end 41. Preferably the compression section 39 is made relatively stiff compared to tension sections 36 and 37 by an embossed ridge 42 extending along a major portion of its length. The stiffening provided by the embossment 42 contributes significantly to the precision of the switch operations as will be discussed more fully hereinafter.

Engaging the snap spring 31 and cooperating therewith in the switching function is a resiliently deflectible operator 43 which is of special significance in the practice of this invention as embodied in the construction shown in FIGURES 1, 2 and 3. The resilient operator 43, preferably formed of a spring material which may be blanked out of sheet stock, comprises a compression member portion 44 including resiliently deflectible spaced arms 45 and 46 connected by a base portion 47 forming therewith a configuration which is roughly U-shaped. Arm 45 includes at its terminus a tab 48 engaging the walls of slot 49 in the fixed end of snap spring 31. The opposite arm 46 includes a recurved portion 50 which bears against the of thecompression section 39 of the snap spring 31.

The dimensions of the interengaging parts of the compression member portion 44 of the resilient operator 43 and of the snap spring 31 are such that the compression section 39 and the compression members 44, which cornprises arms 45 and 46, are placed under compression creating a bistable condition of the snap spring 31. FIG- URE 1 illustrates the unactuated condition of the switch in which the free end 41 of the compression section 39 is above the general plane of the snap spring 31 and in which the movable contact 34 bears against the stationary contact 26. The actuated condition of the switch is illus- 4 trated in FIGURE 2 wherein it can be seen that the free end 41 of compression section 39 has been deflected overcenter through the general plane of the snap spring 31, thereby forcing an upward deflection of the contact-carrying end to a point limited by the engagement of the movable contact 35 with the upper fixed contact 27.

It is to be noted that the resiliently deflectible operator 43 includes a cantilever leaf spring section 51 which is bifurcated at one end and connected to the base portion 47 of the compression member 44. The cantilever spring section 51 extends into engagement at its opposite end with a recessed portion 52 formed in the housing 20. The housing 20 includes a pair of shoulders 53 and 54 adjacent recessed portion 52 which bear against the leaf spring 51 limiting its permissible movement. In the unactuated condition illustrated in FIGURE 1 the cantilever spring 51 is not highly stressed. However, when the switch is actuated as shown in FIGURE 2, the leaf spring is flexed and exerts a return force upon the compression member 44 and through it upon the snap spring 31 tending to restore these elements to their unactuated positions.

In the embodiment illustrated in FIGURES l, 2 and 3, the actuating member for the switch is constituted by a pushbutton 55 movable within a still further slot 56. The slot 56 is in communication at one end with the interior of chamber 21 within the switch housing and at its other end with the exterior of the housing. The actuating member 55 includes a shoulder 57 trapped within an enlargement of the slot 56 to limit inward and outward movements thereof. At its innermost end the pushbutton member 55 terminates in two pointed projections 58 and 59 which straddle the base portion 47 of the compression member 44 and bear against the two arms at the bifurcated end of leaf spring 51.

This type of construction results in a very fast acting switch which gives high contact pressures virtually to the point of contact separation with a high velocity break as the contacts part at actuation. The reason for the high velocity contact separation is that during actuation either in one direction or in the other a spring force is stored in the compression member 44. By comparison between FIGURES 1 and 2, it can be seen that the actuating member 55 does not engage directly the compression member 44 but engages the leaf spring portion 51 of the operator. Consequently, in depressing the pushbutton 55, a certain energy is stored in the U-shaped compression member which may be rapidly and efficiently imparted to the snap spring 31 regardless of the speed at which the pushbutton is depressed. When the pushbutton is released and the cantilever spring 51 starts to restore the switch from the condition illustrated in FIGURE 2 to that shown in FIG- URE 1, energy is again stored in the compression member portion of the resilient operator. As a result the movable contacts during disengagement with either of the fixed contacts 26 or 27 experience a very rapid transfer through zero contact pressure.

The embossment 42 on the compression section 39 of the snap spring contributes significantly to the speed and precision of the high velocity switch actuation which takes place. Because of the additional stiffening imparted to the compression section, any tendency of this portion of the snap spring to assume a curved configuration during the switching action is inhibited. If the compression section 39 were as flexible as the tension sections 36 and 37, the speed at which the movable contacts separate from the fixed contacts might be reduced.

The formation of a substantial curvature of the compression section 39 during actuation in either direction would represent an inefficient diversion of available energy into the flexing of compression section 39 rather than into the motion of the movable contacts. By making the compression section 39 substantially rigid this temporary diversion of switching force and energy is minimized and both the speed and precision of contact action is improved. Instead of thickening the compression member or aflixing a plate thereto, the use of an embossment such as 42 is preferred for stiffening the compression section because the movable mass is minimized and the speed of operation is thereby enhanced.

An alternate embodiment of the invention is shown in FIGURES 4 and 5. Those elements of these two figures which are identical in construction with elements of the preceding embodiment are identified by the same reference number. Consequently, no effort will be made to duplicate the description of these identical elements in connection with FIGURES 4 .and 5. Herein, the resilient operator 70 is seen to have a slightly different configuration from that of the resilient operator in the previous embodiment. A compression member portion 71 of the resilient operator comprises two resiliently deflectible arms 72 and 73 connected by a base portion 74. Recurved portions 75 of deflectible arm 72 engages a slotted portion of the snap spring 31 adjacent the fixed end of the snap spring. Recurved portion 76 of arm 73 on the other hand, bears against the free end 41 of the compression section 39 of the snap spring. In this embodiment the channel-shaped configuration of the compression member 71 is more clearly apparent than in the previous example because of the symmetry of the arms 72 and '73.

As best seen in FIGURES 6, a leaf spring section 77 of the resilient operator 70 is connected by bifurcated arms 78 and 79 to the base portion 74 of the compression member 71. The opposite end of the leaf spring section 77, as in the previous embodiment, is again trapped between shoulders 53 and 54 adjacent the recessed portion 52 in the switch housing. The actuating member 81 in this embodiment is also of somewhat different construction. Although the end 82 which projects from the switch housing and the shoulder 83 which is trapped for limited movement wtihin an enlargement of the slot 56 are similar to the corresponding portions of the previously described actuating member, the innermost end of the actuating pushbutton member 81 terminates in a single pointed projection 84 bearing against base portion 74 at a position adjacent the resiliently deflectible arm 73.

This construction is particularly useful wherever high precision in the switching function is desired to a greater extent than high velocity contact separation. Because the switch actuating member bears directly against the compression member base portion 74 of the resilient operator and not directly against the leaf spring section 77, less energy is stored in the compression member base portion during operation. Consequently, the point of switch actuation is determined by the precise position reached by the switch actuating member 81 in its downward travel as seen in FIGURES 4, 5 and 6. When the compression section 3% of the snap spring 31 reaches a position fractionally overcenter past the point of maximum compression, i.e. when it passes through the plane of the snap spring 31, the movable switch contacts reverse their positions. Although the speed of contact separation is still quite rapid and snap acting, a principal advantage gained with this construction is high precision operation.

At this point it is in order to pause and consider some of the salient features of both switch constructions shown in FIGURES 1 through 3 and in FIGURES 4 through 6, respectively. It is to be noted that all the internal parts positioned within the switch housing in both embodiments can he slipped into position without any special mounting or fastening devices. The terminal members and the pushbutton actuator are simply dropped into their respective slots and the cantilever spring into its recess. Once in position, the operation of the switch parts can be immediately observed and tested if desirable. The trouble-free cantilever spring, which in these embodiments constitutes an integral part of the resilient operator, provides a full restorative force to return the movable switch contacts to their unactuated position with- I out the necessity of using arrangements difficult to install.

Particularly isit to be noted that the simplest substitution in either of these .two embodiments converts the basic switch from high speed operation to high precision operation or vice versa. If, for example, the pushbutton actuating member 55 shown in FIGURE 3 were substituted for the pushbutton actuating member 81 of FIG- URE 6, the second illustrated embodiment of the invention immediately acquires a high velocity operation instead of a high precision operation. Such a substitution is illustrated in FIGURE 7, which shows a switch construction totally equivalent to that of FIGURE 5, but with pushbutton actuator 55 substituted in place of pushbutton actuator 81. In this instance, the actuator bears directly against the bifurcated arms of the leaf spring '77 and permits substantial energy to be stored in the compression member portion of the resilient operator. The energy stored, being substantially independent of the speed at which the pushbutton is depressed, imparts a very high speed movement to the movable contacts during actuation or reverse actuation.

A still further embodiment of the invention is shown in FIGURES 8, 9 and 10, wherein elements identical to those in previous embodiments are designated by the same reference numbers. The principal difference reflected in this embodiment is that the resilient operator is composed of two interconnected parts instead of an integral onepiece element. As can best be seen in FIGURE 10, the compression member 91 comprising the two resiliently deflectible arms 92 and 93, includes a slot 94 therein. Into the slot extends one end of an independent leaf spring 95 to bear against the base portion 96 of the compression member. The opposite end of the leaf spring 95 is captive within recess 52 of the housing and its position is secured by ears 97 and 98 extending transversely from the captured end and interfitting with cooperative contours formed in the housing parts. It can thus be seen that the functions of the compression member Q1 and of the restorative cantilever springs 95 are provided by a pair of members in this embodiment rather than by a single multifunction element.

As seen in FIGURES 8 and 9, the pushbutton actuating member 81 bears against the compression member 91 in its downward movement. Because little energy is stored in the compression member 91 during actuation or reverse actuation, the operation of the switch is characterized by high precision in accordance with the principles previously discussed.

In FIGURE 11 is illustrated a substitution which converts the switch to another mode of operation. Among the three elements illustrated in this exploded perspective view, the pushbutton actuating member 81 and the independent leaf spring 95 are identical to those shown in FIGURE 10. An alternate compression member 101 is installed in this combination. The compression member 101 is slit along its base portion 102 to form an integral resilient center leg Hi3 having a free end 1M extending toward the cantilever spring 95. The resiliently deflectible arms 105 and 1% are installed in compression on the snap spring with the leaf spring 95 extending into the space beneath the resilient center leg 163 and bearing upward against the free end 104. The lower portion of the pushbutton actuator 81 bears against the resilient center leg N3 flexing it downward as the pushbutton is depressed. During actuation therefore the compression member lags slightly behind the actuating member and energy is stored within the compression member 101. It is this energy which, at a critical point in the actuation of the switch, exerts a very fast and very positive movement upon the movable end of the contact-carrying snap spring. When the cantilever spring returns the contacts to their original unactuated condition, a similar effect takes place.

The embodiments of the invention shown in the accompanying drawings and described above are, of course, intended as illustrative and not necessarily limiting upon 7 the true spirit and scope of this invention in its broader aspects. Numerous modifications in the invention, in addition to those already described, may be made without departing ijrom the practice of the invention. For example, the limits of movement of the contact-carrying snap spring 31 need not be defined only by the engagement between the fixed and movable contacts, for the compression section 39 may also engage fixed stops such as abutments 107 and 108 in FIGURES 8 and 9 to prevent the free end 41 from travelling too far on the upper or lower sides of the snap spring. The configurations of the several elements including the housing, the actuating members, the resilient operators, snap springs and the contacts may vary widely. Furthermore, it is not essential that two sets of fixed contacts be provided if single pole operation is desired. Consequently, the appended claims are intended to encompass all proper modifications of the invention set forth herein.

What is claimed is: 1. A snap switch comprising in combination: an elongated snap spring having one end fixedly mounted with its opposite end movable between unactuated and actuated positions, said snap spring including a tension section and compression section terminating in a free end; a movable contact mounted on the movable end of said snap sprin means including a fixed contact "for engaging said movable contact in one of said positions or said snap sprin-g; operator means including a compression member portion having a pair of resiliently defiectible spaced arms connected by a base, one of said arms being pivotally mounted at a fixed position, the other of said arms bearing against the free end of said compression section to place said compression section in compression and said tension section in tension, said operator means further including a return leaf spring portion connected at one end to said compression member portion and fixed at its other end, said return leaf spring portion being resiliently flexed when said snap spring moves from said unactuated position to said actuated position; and actuating means engageable with said operator means for displacing said compression member portion and for flexing said return leaf spring portion to move said snap spring from its unactuated position to its actuated position, said return leaf spring portion exerting sufficient force on said compression member portion to restore said snap spring to said unactuated condition upon release of said actuating means. 2. A snap switch comprising in combination: an elongated snap spring having one end fixedly mounted with its opposite end movable between unactuated and actuate-d positions, said snap spring including a tension section and a compression section terminating in a free end; a movable contact mounted on the movable end of said snap spring; means including a fixed contact for engaging said movable contact in one of said positions of said snap spring; operator means including a compression member portion having a pair of resiliently deflectible spaced anms connected by a base, one of said arms being pivotally mounted at a fixed position, the other of said arms bearing against the free end of said compression section to place said compression section in compression and said tension section in tension, said operator means further including a return spring portion connected at one end to said compression member portion and fixed at its other end,

said return spring portion being resiliently flexed when said snap spring moves from said unactuated position to said actuated position; and

actuating means engageable with the return spring portion of said operator means 'for displacing said compression member portion and for flexing said return spring portion to move said snap spring from its unactuated position to its actuated position,

said return spring portion exerting sufiicient force on said compression member portion to restore said snap spring to said unactuated condition upon release of said actuating means.

3. A snap switch comprising in combination:

an elongated snap spring having one end fixedly mounted with its opposite end movable between unactuated and actuated positions,

said snap spring including a tension section and a compression section terminating in a free end;

a movable contact mounted on the movable end of said snap sprin means including a fixed contact for engaging said movable contact in one of said positions of said snap spring;

operator means including a compression member portion having a pair of resiliently deflectible spaced arms connected by a base,

one of said arms being pivotally mounted at a fixed position, the other of said arms bearing against the free end of said compression section to place said compression section in compression and said tension section in tension,

said operator means i urther including a return spring portion connected at one end to said compression member portion and fixed at its other end,

said return spring portion being resiliently flexed when said snap spring moves from said unactuated position to said actuated position; and

actuating means engageable with the compression member portion of said operator means for displacing said compression member portion for flexing said return spring portion to move said snap spring from its unactuated position to its actuated position,

i said return spring portion exerting sufficient force on said compression member portion to restore said snap spring to said unactuated condition upon release of said actuating means. 4. A snap switch comprising in combination: an insulating housing; an elongated generally planar snap spring having one end fixedly mounted in said housing with its opposite end movable between unactuated and actuated positions, said snap spring including at least one tension section and at least one compression section extending from the movable end of said snap spring toward the fixed end thereof and terminating in a free end; at least one movable contact mounted on the movable end of said snap spring; means including at least one fixed contact for engaging said movable contact in one of said positions of said snap spring; resiliently deflectible operator means including a compression member having a pair of resiliently deflectible spaced arms connected by a base, one of said arms being pivotally mounted at a fixed position adjacent the fixed end of said snap spring, the other of said arms bearing against the free end of said compression section to place said compression section in compression and said tension section in tension, said resilient deflectible operator means further including a cantilever spring connected at one end to said d) compression member and held captive at its other end in said housing,

said cantilever spring being resiliently flexed when said snap spring moves from said unactuated position to said actuated position; and

a movable actuating member engageable with said resiliently deflectible operator means for displacing said compression member and for flexing said cantilever spring to move said snap spring from its unactuated position to its actuated position,

said cantilever spring exerting sufficient force on said compression member to restore said snap spring to said unactuated position upon release of said actuating member.

5. A snap switch comprising in combination:

an insulating housing;

an elongated generally planar snap spring having one end fixedly mounted in said housing with its opposite end movable between unactuated and actuated positions,

said snap spring including a pair of flexible tension sections connected together at the fixed and movable ends thereof and including an inner substantially rigid compression section extending from the movable end of said snap spring toward the fixed end thereof and terminating in a free end;

at least one movable contact mounted on the movable end of said snap spring;

means including at least one fixed contact for engaging said movable contact in one of said positions of said snap spring;

a resiliently deflectible operator including a compression member portion having a pair of resiliently dey flectible spaced arms connectedby a base, one of said arms being pivotally mounted at a fixed position adjacent the fixed end of said snap spring, the other of said arms bearing against the free end of said compression section to place said section in compression and said tension sections in tension, said resiliently deflectible operator further including an elongated cantilever spring connected integrally at one end to said compression member and extending at its other end into engagement with said housing,

said cantilever spring portion being resiliently flexed when said snap spring moves from said unactuated position to said actuated position; and

a movable actuating member engageable with said operator for displacing said compression member portion and for flexing said cantilever spring portion to move said snap spring from its unactuated position to its actuated position,

said cantilever spring exerting suflicient force on said compression member portion to restore said snap spring to said unactuated condition upon release of said actuating member;

6. The combination of claim wherein said actuating member engages the cantilever spring portion of said operator during actuation of said switch.

7 The combination of claim 5 wherein said actuating member engages the compression member portion of said operator during actuation of said switch.

8. A snap switch comprising in combination:

an elongated snap spring having one end fixedly mounted and its opposite end movable between unactuated and actuated positions,

said snap spring having a tension section and a compression section, said compression section having a free end;

at least one movable contact mounted on the movable end of said snap spring;

means including at least one fixed contact for engaging said movable contact in one of said positions of said snap spring;

a resilient member having a pair of spaced legs,

one of said legs being pivotally mounted at a fixed position, the other of said legs bearing pivotally against the free end of said compression section,

movable actuating means for displacing said resilient member and said compression section relative to said tension section to effect snap movement of said tension section and said movable contact relative to said fixed contact; and return spring means deflectible in response to displacement of said resilient member.

9. A snap switch comprising in combination:

an elongated snap spring having one end fixedly mounted and its opposite end movable between unactuated and actuated positions,

said snap spring having a tension section and a compression section, said compression section having a free end;

at least one movable contact mounted on the movable end of said snap spring;

means including at least one fixed contact for engaging said movable contact in one of said positions of said snap spring;

a generally U-shaped resilient member having a pair of spaced legs connected by a base,

one of said legs being pivotally mounted on said tension section at the fixed end thereof, the other of said legs bearing pivotally against the free end of said compression section,

movable actuating means for displacing said resilient member and said compression section relative to said tension section to effect snap movement of said tension section and said movable contact relative to said fixed contact; and return spring means deflectible in response to displacement of said resilient member.

10. A snap switch comprising in combination:

an elongated snap spring having one end fixedly mounted and its opposite end movable between unactuated and actuated positions,

said snap spring having a tension section and a compression section, said compression section having a free end;

at least one movable contact mounted on the movable end of said snap spring;

means including at least one fixed contact for engaging said movable contact in one of said positions of said snap spring;

a channel-shaped resilient compression member having a pair of spaced arms connected by a base,

one of said arms being pivotally mounted at a fixed position, the other of said arms bearing pivotally against the free end of said compression section;

a cantilever spring having a fixed end and a deflectible end bearing against the base of said compression member urging said snap switch toward its unactuated position; and

movable actuating means for moving said compression member against the force of said cantilever spring to effect movement of snap spring to said actuated position.

11. A snap switch comprising in combination:

an elongated snap spring having one end fixedly mounted and its opposite end movable between unactuated and actuated positions,

said snap spring having a tension section and a compression section, said compression section having a free end;

at least one movable contact mounted on the movable end of said snap spring;

means including at least one fixed contact for engaging said movable contact in one of said positions of said snap spring;

a resilient member having a pair of spaced legs connected by a base;

a deflectible part struck out from said base,

one of said legs being pivotally mounted on the fixed end of said tension section, the other of said legs bearing pivotally against the free end of said compression section,

movable actuating means engagable with said deflectible part for displacing said resilient member and said compression section relative to said tension section to eifect snap movement of said tension section and said movable contact relative to said fixed contact; and

a return spring engageable by said resilient member to establish a return force in response to displacement of said resilient member.

12. A snap switch comprising in combination:

an elongated snap spring having one end fixedly mounted and its opposite end movable between unactuated and actuated positions,

said snap spring having a tension section and a compression section, said compression section having a free end;

at least one movable contact mounted on the movable end of said snap spring;

means including at least one fixed contact for engaging said movable contact in one of said positions of said snap spring;

a channel-shaped resilient compression member having a pair of spaced arms connected by a base, said base having a cantilever spring section struck out therefrom,

one of said arms being pivotally mounted on said tension section, the other of said arms bearing pivotally against the free end of said compression section;

a separate cantilever spring having a fixed end and a deflectible end bearing against the cantilever spring section of said compression member to urge said snap switch toward its unactuated position; and

movable actuating means engageable with the cantilever spring section of said compression member to move said compression member against the force of said cantilever spring to effect movement of said snap spring to said actuated position.

13. A snap switch comprising in combination:

an insulating housing,

an elongated snap spring including a flexible tension section,

means mounting one portion of said tension section fixedly in said housing and permitting deflection movements of an end of said tension section,

said snap spring further including a substantially rigid compression section connected to said tension section at the movable end thereof and extending towards the fixed portion thereof;

a resiliently deflectible member compressed between the free end of said compression section and a fixed position;

movable electrical contact means mounted on the movable end of said snap spring;

fixed electrical contact means positioned for engagement by said movable contact means;

a cantilever return spring having one end connected to said deflectible member and having its other end held captive by said housing; and

a movable actuating member for acting on said resiliently deflectible member to control engagements between said fixed and movable contact means.

14. The snap switch defined in claim 5, wherein said one end of said elongated cantilever spring is bifurcated to form a pair of arms integrally connected to said base of said compression member and between which said other of said arms of said compression member portion is located.

References Cited by the Examiner UNITED STATES PATENTS 9/1947 Miller. 4/1961 Haydon. 

1. A SNAP SWITCH COMPRISING IN COMBINATION: AN ELONGATED SNAP SPRING HAVING ONE END FIXEDLY MOUNTED WITH ITS OPPOSITE END MOVABLE BETWEEN UNACTUATED AND ACTUATED POSITIONS, SAID SNAP SPRING INCLUDING A TENSION SECTION AND COMPRESSION SECTION TERMINATING IN A FREE END; A MOVABLE CONTACT MOUNTED ON THE MOVABLE END OF SAID SNAP SPRING; MEANS INCLUDING A FIXED CONTACT FOR ENGAGING SAID MOVABLE CONTACT IN ONE OF SAID POSITIONS OF SAID SNAP SPRING; OPERATOR MEANS INCLUDING A COMPRESSION MEMBER PORTION HAVING A PAIR OF RESILIENTLY DEFLECTIBLE SPACED ARMS CONNECTED BY A BASE, ONE OF SAID ARMS BEING PIVOTALLY MOUNTED AT A FIXED POSITION, THE OTHER OF SAID ARMS BEARING AGAINST THE FREE END OF SAID COMPRESSION SECTION TO PLACE SAID COMPRESSION SECTION IN COMPRESSION AND SAID TENSION SECTION IN TENSION, SAID OPERATOR MEANS FURTHER INCLUDING A RETURN LEAF SPRING PORTION CONNECTED AT ONE END TO SAID COMPRESSION MEMBER PORTION AND FIXED AT ITS OTHER END, SAID RETURN LEAF SPRING PORTION BEING RESILIENTLY FLEXED WHEN SAID SNAP SPRING MOVES FROM SAID UNACTUATED POSITION TO SAID ACTUATED POSITION; AND ACTUATING MEAND ENGAGEABLE WITH SAID OPERATOR MEANS FOR DISPLACING SAID COMPRESSION MEMBER PORTION AND FOR FLEXING SAID RETURN LEAF SPRING PORTION TO MOVE SAID SNAP SPRING FROM ITS UNACTUATED POSITIONN TO ITS ACTUATED POSITION, SAID RETURN LEAF SPRING PORTION EXTRTING SUFFICIENT FORCE ON SAID COMPRESSION MEMBER PORTION TO RESTORE SAID SNAP SPRING TO SAID UNACTUATED CONDITION UPON RELEASE OF SAID ACTUATING MEANS. 